The present invention relates to a nondestructive inspection apparatus; and, in particular, to a nondestructive inspection apparatus utilizing an open type X-ray generating apparatus making it possible to replace a filament part, which is a consumable, upon vacuum aspiration by use of a pump.
An X-ray generating apparatus utilized in such a field has conventionally been known from Japanese Patent Application Laid-Open No. HEI 10-503618. In the X-ray generating apparatus disclosed in the above-mentioned publication, electron beams emitted from a cathode are focused onto a target by an electromagnetic action of a coil, whereby an X-ray beam is emitted from a target toward an object to be inspected. Here, since the X-ray generating apparatus operates at a very high voltage of 160 kV, it has a separate, large-size, high-voltage power unit which is connected to the X-ray generating apparatus by a high-tension cable.
Since the high-voltage power unit for driving the X-ray generating apparatus has a structure for generating a very high voltage of 100 kV to 300 kV, however, the high-tension cable for transmitting this voltage to the X-ray generating apparatus must become very thick (e.g., a diameter of 40 mm) and heavy. The handling of such a high-tension cable is required to be managed quite strictly. Namely, the degree of freedom in bending this high-tension cable is very low because of its high-tension characteristics and structure, whereby extreme caution must be taken to prevent disasters from occurring due to electric leakage upon connection to the X-ray generating apparatus, and periodical maintenance is necessary for preventing electric leakage from occurring from a connecting part, thus putting an excessive load on operators and users. In addition, the weight of high-tension cable has been a factor further enhancing the burden of operators.
When such an X-ray generating apparatus is placed in a nondestructive inspection apparatus, the high-tension cable has a very low degree of freedom in bending, whereby the X-ray generating apparatus will be placed under a suspending state in the nondestructive inspection apparatus if the high-tension cable is one extending from the lower part of the X-ray generating apparatus, thus yielding an unstable fixing state. Such a restriction results from the difficulty in traveling of the high-tension cable.
For overcoming the problem mentioned above, it is an object of the present invention, in particular, to provide an on destructive inspection apparatus which can stably place an open type X-ray generating apparatus making its filament part replaceable.
The nondestructive inspection apparatus of the present invention is a nondestructive inspection apparatus for irradiating an object to be inspected with an X-ray generated from an open type X-ray generating apparatus which irradiates a target with an electron emitted from an electron gun having a replaceable filament part so as to release the X-ray from the target, and capturing a state of the object to be inspected with an X-ray camera; the open type X-ray generating apparatus comprising a tubular portion, adapted to be vacuumed by a pump, having a coil part therewithin and an electron path surrounded by the coil part; and a mold power unit, secured to a proximal end side of the tubular portion, having a resin-molded high-voltage generating part; wherein the mold power unit is secured to a base plate while in a state where the target disposed on one end side of the tubular portion and the mold power unit disposed on the other end side of the tubular portion are located on the upper and lower sides, respectively.
This nondestructive inspection apparatus utilizes vacuum aspiration effected by the pump, so as to make it possible to replace the filament part, which is a consumable, thereby improving the maintenance. Such an apparatus is required to have not only durability but also easiness in handling. Hence, for eliminating the high-tension cable in order to improve the handling, a mold power unit in which a high-voltage generating part attaining a high voltage (e.g., 160 kV) is molded with a resin is employed, whereas this mold power unit is secured to the proximal end side of the tubular portion, whereby an apparatus of a type integrated with a power supply is realized. Since the high-voltage generating part is confined within the resin mold as such, the degree of freedom in configuration of the high-voltage generating portion improves remarkably. Also, since the heavy mold power unit and the target are located on the lower and upper sides, respectively, the X-ray generating apparatus can be placed in the nondestructive inspection apparatus while in a stable state. In addition, since the conventional necessity for the high-tension cable is eliminated, the heavy mold power unit can be secured onto the base plate of the nondestructive inspection apparatus, whereby the X-ray generating apparatus can further be stabilized.